3a,4,7,7a-tetrahydro-4,7-methanoindene

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP compliant, guideline study, available as unpublished report, no restrictions, fully adequate for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Deviations:

no

Principles of method if other than guideline:

n/a

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Reference substance 001

Cas Number:

77-73-6

Molecular formula:

C10H12

Constituent 2

Reference substance name:

Dicyclopentadiene resin grade

IUPAC Name:

Dicyclopentadiene resin grade

Test material form:

liquid

Details on test material:

- Name of test material (as cited in study report): Dicyclopentadiene resin grade
- Physical state: clear light yellow liquid
- Analytical purity: 75%
- Lot/batch No.: TNZ001
- Expiration date of the lot/batch: 1 April 2000
- Storage condition of test material: room temperature in dark

Specific details on test material used for the study:

- Name of test material (as cited in study report): Dicyclopentadiene resin grade
- Physical state: clear light yellow liquid
- Analytical purity: 75%
- Lot/batch No.: TNZ001
- Expiration date of the lot/batch: 1 April 2000
- Storage condition of test material: room temperature in dark

Method

Target gene:

n/a

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Cytokinesis block (if used):

n/a

Metabolic activation:

with and without

Metabolic activation system:

S9 from Arochlor 1254 induced rat liver

Test concentrations with justification for top dose:

Dose range 1-666 µg/plate

Vehicle / solvent:

Vehicle(s)/solvent(s) used: ethanol

Controls

Negative solvent / vehicle controls:

yes

Remarks:

ethanol

Positive controls:

yes

Positive control substance:

other: sodium azide, 9-aminoacridine, daunomycine, methylmethanesulfonate, 4-nitroquinoline N-oxide, 2 aminoanthracene

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 30 minutes
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: 2

DETERMINATION OF CYTOTOXICITY
- Method: observation of reduction of bacterial background lawn, reduction in revertant colonies

Evaluation criteria:

Negative (ie non-mutagenic) if:
a) total number of revertants in tester strain at any concentration is not > 2 x solvent control value for TA100 and 3 x solvent control value for TA1535, TA1537, TA98 and WP2uvrA +/- activation
b) Negative response should be repeatable in at least one independently repeated expt.
Positive (ie mutagenic) if:
a) it produces at least a 3-fold (TA1535, TA1537, TA98 and WP2uvrA) or 2-fold (TA100) dose-related increase in the number of revertants with respect to the number induced ny solvent control in TA100 +/- activation. However any mean plate count < 20 is considered to be not significant
b) Positive response should be repeatable in at least one independently repeated expt.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

n/a

Any other information on results incl. tables

n/a

Applicant's summary and conclusion

Conclusions:

Interpretation of results:
negative with metabolic activation
negative without metabolic activation

Dicyclopentadiene resin grade is not mutagenic in the Salmonella typhimurium reverse mutation assay or in the Escherichia coli reverse mutation assay.

Executive summary:

In this OECD 471 guideline study, dicyclopentadiene resin grade did not induce a dose-related or a two-fold, increase in the number of revertant (His⁺) colonies in any of the four tester strains (TA1535, TA1537, TA98 and TA100) nor in the number of revertant (Trp⁺) colonies in tester strain WP₂uvrA both in the absence and presence of S9-metabolic activation. These results were confirmed in an independently repeated experiment.

Therefore, it was concluded that dicyclopentadiene resin grade is not mutagenic in the Salmonella typhimurium reverse mutation assay or in the Escherichia coli reverse mutation assay.